Satisfactory clinical outcome of operative and non-operative treatment of avulsion fracture of the hamstring origin with treatment selection based on extent of displacement: a systematic review

PURPOSE: To compare outcome of operative and non-operative treatment of avulsion fractures of the hamstring origin, with minor (< 1.5 cm) and major (≥ 1.5 cm) displacement, and early (≤ 4 weeks) and delayed (> 4 weeks) surgery. METHODS: A systematic literature search was performed using PubMed, Cochrane, Embase, CINAHL and SPORTDiscus. A quality assessment was performed using the Physiotherapy Evidence Database (PEDro) scale. RESULTS: Eight studies with 90 patients (mean age: 16 years) were included. All studies had low methodological quality (PEDro score ≤ 5). Operative treatment yielded a return to preinjury activity rate (RTPA) of 87% (95% CI: 68–95), return to sports (RTS) rate of 100% (95% CI: 82–100), Harris hip score (HHS) of 99 (range 96–100) and a University of California Los Angeles activity scale (UCLA) score of 100%. Non-operative treatment yielded a RTPA rate of 100% (95% CI:68–100), RTS rate of 86% (95% CI: 69–94), HHS score of 99 (range 96–100), and non-union rate of 18% (95% CI: 9–34). All patients with minor displacement were treated non-operatively (RTPA: 100% [95% CI: 21–100], RTS: 100% [95% CI: 51–100]). For major displacement, operative treatment led to RTPA and RTS rates of 86% (95% CI: 65–95) and 100% (95% CI: 84–100), and 0% (0/1, 95% CI: 0–79) and 100% (95% CI: 51–100) for non-operative treatment. Early surgery yielded RTPA and RTS rates of 100% (95% CI: 34–100 & 57–100) compared to 100 (95% CI: 72–100) and 90% (95% CI: 60–98) for delayed repair. CONCLUSION: All included studies have high risk of bias. There is only low level of evidence with a limited number of included patients to compare outcome of operative and non-operative treatment. Overall outcome was satisfactory. There is a treatment selection phenomenon based on displacement, with acceptable outcome in both groups. There is insufficient data to draw conclusions regarding timing of surgery. LEVEL OF EVIDENCE: IV ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1007/s00167-020-06222-y) contains supplementary material, which is available to authorized users.